Add CI using GitHub Actions

Ref: lxqt/lxqt#1644

.ci/build.sh

@@ -0,0 +1,9 @@
+set -ex
+
+source shared-ci/prepare-archlinux.sh
+
+# See *depends in https://github.com/archlinuxcn/repo/blob/master/archlinuxcn/qterminal-git/PKGBUILD
+pacman -S --noconfirm --needed git cmake lxqt-build-tools-git qt5-tools qtermwidget-git qt5-x11extras qt5-translations
+
+cmake -B build -S .
+make -C build

.github/workflows/test.yml

@@ -0,0 +1,18 @@
+name: Testing
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-20.04
+    container: archlinux:base-devel
+    steps:
+    - name: Checkout the repo
+      uses: actions/checkout@v2
+    - name: Checkout shared CI repo
+      uses: actions/checkout@v2
+      with:
+        repository: lxqt/ci
+        path: shared-ci
+    - name: Build
+      run: bash ./.ci/build.sh